Concise Bible Dictionary:
The “teacher” is one of the gifts set in the church (1 Cor. 12:28; Eph. 4:11); and the teacher is exhorted to be occupied with teaching (Rom. 12:7). “Teaching” is the intelligent setting forth of the truth by the Holy Spirit, and this does not leave room for the mind and opinion of man. Paul left Timothy at Ephesus to charge some not to teach other doctrine than what the apostles taught; and those that did teach otherwise are said to be “puffed up, knowing nothing” (1 Tim. 1:3; 1 Tim. 6:3-4). This makes evident that no other teaching could be of God; hence the modern formula of “agreeing to differ” on vital points of doctrine is not recognized. On the contrary, the apostle said, “I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment” (1 Cor. 1:10).
A caution is given in James 3:1, “Be not many teachers,” for it involved greater responsibility. The same word (διδάσκαλος) occurs in John 13:13, where the Lord owned Himself to be the Teacher, and He was many times addressed as “Teacher”; though in nearly all cases the AV has “Master.” He taught as one having authority, and not as the scribes.